The cyclic loads effect on mechanical strength was studied in the research of ZP-K mechanical properties covering for anticorrosive protection of steel vertical cylindrical tank inner surface. The experimental models produced from the templates were chosen as a test subject. The templates were cut from the generatrix of steel vertical cylindrical tank having operated for more than thirty years. The material of the experimental models is carbon steel. The results of effect estimation on fatigue resistance of protactive coating according to relative deformation, holding period of coating after its application on models surface were introduced. The results of effect estimation of backing quality were introduced. The same research work was done with the experimental models produced from carbon steel that was not used before for results comparison and specification.